BOSTON Marathon bombing suspect Dzhokhar Tsarnaev scribbled a note on the boat he hid in during a city-wide manhunt.

Tsarnaev wrote with a pen on the inside wall of the boat’s cabin, said the bombings were payback for US military action in Iraq and Afghanistan, and said he would not miss his older brother Tamerlan Tsarnaev, who was killed in an earlier police shoot-out, CBS news reports.

He called the victims of the bombings collateral damage, and compared it to Muslims who have been killed in US-led wars in Iraq and Afghanistan.

"When you attack on Muslim, you attack all Muslims," he scrawled with a pen on the wall.

Tsarnaev wrote that his older brother was now a martyr in paradise and that he expected to join him there.

The brothers allegedly set off the bombs that killed three people and injured more than 260 at the Boston Marathon on April 15.